• Journal of Astronomy and Space Sciences
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• v.33 no.3
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• pp.177-183
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• 2016

Active galactic nuclei (AGN) are too compact to be resolved by any existing optical telescope facility, making it difficult to understand their structure and the emission processes responsible for their huge energy output. However, variability, one of their characteristic properties, provides a tool to probe the inner regions of AGN. Blazars are the best candidates for such a study, and hence a considerable amount of effort is being made to investigate variability in these sources across the electromagnetic spectrum. Here, using the Mt. Abu infrared observatory (MIRO) blazar monitoring program, we present intra-night, inter-night, and long term aspects of the variability in S5 0716+71, 3C66A, and OJ 287. These stars show significant variability on short (a few tens of mins, to a few hours, to a few days) to long term (months to years) timescales. Based on the light travel time argument, the shortest variability timescales (micro-variability) provide upper limits to the size of the emission region. While S5 0716 shows a very high duty cycle of variability (> 80 %), 3C66A shows a much lower intra day variability (IDV) duty cycle (< 20 %). All three show rapid variations within 2.5 to 3.5 hr, which, perhaps, are generated near the vicinity of black holes. Assuming this, estimates of the masses of the black holes are made at ~10⁹, 8×10⁸, and 2.7×10⁹ M_⨀ for S5 0716+71, 3C66A, and OJ 287, respectively. Multi-wavelength light-curves for the blazar PKS 1510-089 are discussed to infer the emission processes responsible for the recent flaring episodes in this source.

• The Journal of the Korea Contents Association
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• v.11 no.12
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• pp.378-385
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• 2011

The purpose of this study was to investigate the relationship of job-stress, job-family conflict, and mental health according to lifestyles of married office worker. Data were collected by structured questionnaires form 185 married office worker by convenient sampling methods from May to August 2011. In our research outcomes, it found that job-stress was positively related to job-family conflict in the self-belief type, family-centralized type, heeding duty type and creative type. Job-family conflict was negatively related to mental health in the heeding duty type. And job-stress was positively related to metal health in the creative type and individual success pursuing type. These findings show that it is necessary to develop therapeutic psychosocial nursing intervention and to locate social-support-resources for reducing high job-stress, solving job-family conflict, and improving mental health in the married office worker.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.4
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• pp.31-39
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• 2010

Although driving patterns strongly influence greenhouse gas and air pollutant emission rate from light duty vehicles, emission measurements have been mainly based on chassis dynamometer testing with one standard driving pattern. And there has been limited work on quantifying the independent effect of driving parameters on emission rate because of multidimensional nature of real-world driving pattern. The objective of this study is to obtain the quantitative effect of relative positive acceleration (RPA) on vehicle emission rate. RPA has been used to define the occurrence of acceleration demanding large amounts of power in certain driving distance and shown to be a significant affecting parameter for real-world emission rate. 40 driving patterns have been developed with fixed driving parameters to investigate independent effect of RPA. For the same values of average vehicle speed and power, the trend in carbon dioxide emission rate and fuel consumption with respect to RPA is very clear. Emission rate of nitrogen oxide and particulate matter also increase with respect to RPA, but the trend is less clear. Carbon dioxide emission from diesel vehicle appear to be more affected by high accelerations compared to that from gasoline vehicle because of high intake air restriction during acceleration caused by turbocharger and intercooler. The results have implications for the possible reduction of environmental effects through better traffic planning and management, driver education and car design.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.26 no.1
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• pp.75-89
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• 2016

Objectives: The purpose of this study was to investigate job stress and satisfaction by general characteristics of engineers industrial hygiene management, and we expect to provide basic data for strategic plan to strengthen the role related to the job. Methods: The subjects of this study was 184 persons who belong to the Korean Industrial Health Association, and 178 completed questionnaires were analyzed. The survey was conducted from June 29 to July 3, 2015. Conclusions: It is necessary to decrease the stress caused by additional job through increasing manpower and developing detailed manual according to the position and systematic job assignment considering general characteristics. Also, it is judged that job satisfaction should increase by vitalizing mentoring, club, small group activity in workplace for maintaining and improving good personal relationship with team members, and implementing incentive system to acknowledge and reward personal duty result.

• Journal of Korean Academy of Nursing Administration
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• v.17 no.4
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• pp.423-431
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• 2011

Purpose: This study was conducted to investigate the relationship of burn out, emotional labor and self-efficacy in nurses, and to identify predictors of burnout. Method: The participants were 268 nurses working in C university hospital in G city. Data were collected from May 1 to May 31, 2010, and analyzed using SPSS/WIN 12.0. Results: The mean score per item for burnout was 3.13, the mean emotional labor score was 3.15, and the mean of self-efficacy score was 3.42. Burnout showed negative correlation with self-efficacy (r=-.339, p=.000), and showed positive correlation with emotional labor (r=.511, p=.000). Variables that predicted burnout were emotional labor, self-efficacy, gender, number of assigned patient per duty (37.8%). Conclusion: The findings of this study indicate a need to develop programs for nurses to increase self-efficacy and to control the emotion, and the need for further studies to examine causal relationship among burn out, emotional labor and self-efficacy.

• Magazine of the Korean Society of Agricultural Engineers
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• v.41 no.4
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• pp.92-103
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• 1999

Recently structural damage has been frequently observed in reinforced concrete brdiges due to repeated loads such as vehicular traffic an due to continual overloads by heavy duty trucks. Therefore, the purpose of this experimental stduy is to investigate the damage mechanism due to fatigue behavior of high-strength reinforced concrete beams under repeated loads. From the test results, the relation of cycle loading to deflection is on the mid-span , the crack growth and the modes of failure according to cycle number, fatigue life and S-N curve were observed through the fatigue test. Based on the fatigue test results , high-strength reinforced concrete beams failed to 57 ∼66 percent of the static ultimate strength . Fatigue strength aobut two million cycles from S-N curves was certified by 60 percent of static ultimate strength.

• Journal of environmental and Sanitary engineering
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• v.14 no.3
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• pp.139-149
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• 1999

This study was performed to investigate components of organic solvents and present statues of environmental measurements with official records of working environmental measurements of 4,181 workplaces in 3,280 workshops used airborne organic solvents. 1. The mean working hour of 4,181 workplace producing airborne organic solvents in 3,280 workshops was 437±28.7min, but the mean sampling time for measurement of airborne organic solvents was identified to be 254±28.8min. In 73.0% of 4,181 samples the sampling frequencys were Full-period, single sample measurement. 2. The total 54 components of organic solvents were measured in total airborne samples of 4,181 workplace in 3,280 workshops in both of first and second half-year. These were divided into 38 components, Group 1 substances (5 components), Group 2 substances (31 components) and Group 3 substances (2 components), regulated by the Industrial Safety and Health Law, and other 16 components without legal duty of working environment measurement. The most common component in each half-year was Toluene (84.8%, 88.2%), which was followed by Xylene (464.4%, 51.7%), Methyl ethyl ketone (31.1%, 34.4%), n-Hexane (22.7%, 27.8%) and Benzene (20.4%, 21.5%) in frequency. Of legal duty free components, Ethyl benzen, Trimethyl benzene and Pentane were frequently detected. In conclusion, these results show that the present legal classification system of organic solvents needs to revise. Also these results suggest that it must be necessary to analyze the component of airborne organic solvents mixture and to evaluate their effects on workers' health for the effective management of working environment in workshops treating with organic solvents.

• Journal of the Korean Home Economics Association
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• v.32 no.5
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• pp.1-14
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• 1994

This study was to identify variables which were related with middle aged women's identification of child mother-role burden and psychological well-being and to investigate the relationships of mother-role burden and psychological well-being in mid-life. The research data were collected from 578 who were 40-59 year old women in Seoul. The major findings were as follow; (1) the level of middle age women's identification of child was very high and the level of mother-role burden was moderate. the level of psychological well-being was slightly high. (2) Mid-life women's psychological well-being was related to education level income and job. (3) Identification of child was related to educational level having job and income. And mother-role burden was influenced only by education level. (4) Middle aged women's identification of child was positively related mother-role burden. Mother-role burden was negatively related to psychological well-being in mid-life. These findings represented middle aged mother in our society had considerable burden of child but their psychological well-being was not low. Possibly it is due to the fact mothers regard their burden of child as acceptable duty.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.30 no.1
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• pp.66-71
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• 2016

In this study, electrical and spectroscopic characteristics were investigated in the pin to plate discharge of 0.9% weight per unit volume saline solution. The positive and positive- and negative-going dc pulse with 5% duty ratio were applied to tungsten pin electrode. The more amount of discharge current flew in negative discharge. The temperature, which is considered as a local value in the vicinity of vapor of discharge, was about 3,000K which is much higher than the value recommended to be controlled. It can be suggested that not only the temperature of liquid but also the local temperature of vapor is monitored to investigate damages on tissue or cells in biological application.

• Journal of Korean Library and Information Science Society
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• v.42 no.4
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• pp.203-221
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• 2011

This study attempts to investigate the current stage of collection development process in small libraries through case study to eleven small libraries in Yeongnam region. Library collection is the primary element of a library and collection development is the starting point of librarians' duty. The researcher recognized the problems observed in collection development process in the case small libraries and discovered the widespread obstacles restraining the future development. Through the visits and observations, aging book collections, lack of diversity in the form of materials acquired, imbalance in subject distribution, and the imbalance in circulation are identified. Suggestions are to be added: collection development duty can not be fulfilled without proper support by local governments. While small libraries penetrate into peoples' territory, Public libraries should seek to enhance and improve their service orientation as well as a cooperative network with these small libraries.